
<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>baidu_task_1_3</title>	
</head>
<style>

	.wrap{
		background-color: #ccc;
		position: absolute; 
  		left: 0; top: 0; bottom: 0; right: 0;
		width: 400px;
		height: 200px;
		margin: auto;
	}
	.wrap .top{
		position: absolute;
		width: 50px;
		height: 50px;
		border-radius: 0 0 50px 0;
		background-color: #fc0; 
	}
	.wrap .bottom{
		position: absolute;
		width: 50px;
		height: 50px;
		border-radius:50px 0 0 0;
		background-color: #fc0; 
		bottom: 0; right: 0;
	}
</style>
<body>
	<div class="wrap">
		<div class="top"></div>
		<div class="bottom"></div>
	</div>	
</body>
</html>